1 files changed, 95 insertions, 0 deletions
diff --git a/tensorflow/core/lib/core/bit_cast_test.cc b/tensorflow/core/lib/core/bit_cast_test.cc
new file mode 100644
index 0000000000..0ea583e96f
--- /dev/null
+++ b/tensorflow/core/lib/core/bit_cast_test.cc
@@ -0,0 +1,95 @@
+// Unit test for bit_cast template.
+
+#include "tensorflow/core/lib/core/casts.h"
+#include "tensorflow/core/platform/logging.h"
+#include <gtest/gtest.h>
+
+namespace tensorflow {
+
+// Marshall and unmarshall.
+// ISO spec C++ section 3.9 promises this will work.
+
+template <int N>
+struct marshall {
+  char buf[N];
+};
+
+template <class T>
+void TestMarshall(const T values[], int num_values) {
+  for (int i = 0; i < num_values; ++i) {
+    T t0 = values[i];
+    marshall<sizeof(T)> m0 = bit_cast<marshall<sizeof(T)> >(t0);
+    T t1 = bit_cast<T>(m0);
+    marshall<sizeof(T)> m1 = bit_cast<marshall<sizeof(T)> >(t1);
+    ASSERT_EQ(0, memcmp(&t0, &t1, sizeof(T)));
+    ASSERT_EQ(0, memcmp(&m0, &m1, sizeof(T)));
+  }
+}
+
+// Convert back and forth to an integral type.  The C++ standard does
+// not guarantee this will work.
+//
+// There are implicit assumptions about sizeof(float) and
+// sizeof(double). These assumptions are quite extant everywhere.
+
+template <class T, class I>
+void TestIntegral(const T values[], int num_values) {
+  for (int i = 0; i < num_values; ++i) {
+    T t0 = values[i];
+    I i0 = bit_cast<I>(t0);
+    T t1 = bit_cast<T>(i0);
+    I i1 = bit_cast<I>(t1);
+    ASSERT_EQ(0, memcmp(&t0, &t1, sizeof(T)));
+    ASSERT_EQ(i0, i1);
+  }
+}
+
+TEST(BitCast, Bool) {
+  LOG(INFO) << "Test bool";
+  static const bool bool_list[] = {false, true};
+  TestMarshall<bool>(bool_list, TF_ARRAYSIZE(bool_list));
+}
+
+TEST(BitCast, Int32) {
+  static const int32 int_list[] = {0,  1,    100,         2147483647,
+                                   -1, -100, -2147483647, -2147483647 - 1};
+  TestMarshall<int32>(int_list, TF_ARRAYSIZE(int_list));
+}
+
+TEST(BitCast, Int64) {
+  static const int64 int64_list[] = {0, 1, 1LL << 40, -1, -(1LL << 40)};
+  TestMarshall<int64>(int64_list, TF_ARRAYSIZE(int64_list));
+}
+
+TEST(BitCast, Uint64) {
+  static const uint64 uint64_list[] = {0, 1, 1LLU << 40, 1LLU << 63};
+  TestMarshall<uint64>(uint64_list, TF_ARRAYSIZE(uint64_list));
+}
+
+TEST(BitCast, Float) {
+  static const float float_list[] = {0.0,  1.0,   -1.0,  10.0,    -10.0,  1e10,
+                                     1e20, 1e-10, 1e-20, 2.71828, 3.14159};
+  TestMarshall<float>(float_list, TF_ARRAYSIZE(float_list));
+  TestIntegral<float, int32>(float_list, TF_ARRAYSIZE(float_list));
+  TestIntegral<float, uint32>(float_list, TF_ARRAYSIZE(float_list));
+}
+
+TEST(BitCast, Double) {
+  static const double double_list[] = {
+      0.0,
+      1.0,
+      -1.0,
+      10.0,
+      -10.0,
+      1e10,
+      1e100,
+      1e-10,
+      1e-100,
+      2.718281828459045,
+      3.141592653589793238462643383279502884197169399375105820974944};
+  TestMarshall<double>(double_list, TF_ARRAYSIZE(double_list));
+  TestIntegral<double, int64>(double_list, TF_ARRAYSIZE(double_list));
+  TestIntegral<double, uint64>(double_list, TF_ARRAYSIZE(double_list));
+}
+
+}  // namespace tensorflow